The Eastern Front of World War II was a theatre of conflict between the European Axis powers and co-belligerent Finland against the Soviet Union, Poland and other Allies, which encompassed Central Europe, Eastern Europe, Northeast Europe (Baltics), and Southeast Europe (Balkans) from 22 June 1941 to 9 May 1945.
Operation Barbarossa (German: Unternehmen Barbarossa) was the code name for the Axis invasion of the Soviet Union, which started on Sunday, 22 June 1941, during World War II.
The Workers' and Peasants' Red Army (Рабоче-крестьянская Красная армия (РККА), Raboche-krest'yanskaya Krasnaya armiya (RKKA), frequently shortened in Russian to Красная aрмия (КА), Krasnaya armiya (KA), in English: Red Army, also in critical literature and folklore of that epoch – Red Horde, Army of Work) was the army and the air force of the Russian Soviet Federative Socialist Republic, and, after 1922, the Union of Soviet Socialist Republics.
The Soviet Union, officially the Union of Soviet Socialist Republics (USSR) was a socialist state in Eurasia that existed from 1922 to 1991.
The 142nd Rifle Division began service in August, 1939 as a standard Red Army rifle division, which participated in the Winter War against Finland.
The 23rd Army was a Field Army of the Soviet Union's Red Army.